Grate



May 21, 1946.

D. J. MOSSHART GRATE Filed July 24, 1944 3 Sheets-Sheet 2 i o 5 '2 i O o I g o 1 i o l o r- I 0 5 '0 i o f" h INVENTOR DoNA LDJ.MO$SHART.

ATTORNEY D. J. MOSSHART GRATE 3 Sheets-Sheet 3 Filed July 24, 1944 INVENTOR Domqu: J. MossH R'r.

. BY W YM WITNESSES:

ATTORNEY Patented May 21, 1946 GRATE Donald J. Mosshart,. Ardmore, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation,-ofPennsylvania ApplicationJuly 24, 1944, Serial No. 546,295

3 Claims.

This invention relates to stokers, more particularly to those of the spreader or sprinkler type, and has for an object to provide improved grate structure therefor.

Yet another object of the invention is to provide improved composite grate bars of inverted-V formation, together with novelmeans for reciprocating at least a portion of such bars to provide for movement of the fuel bed thereover.

These and other objects are eifected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming-a part of this application, in which:

Fig. 1 is a longitudinal sectional view taken along the line II of Fig. 2, looking in the direction indicated by the arrows; v

Fig. 2 is a transverse sectional view'taken' along the line II-II of Fig. 1, looking in the direction indicated by the arrows;

Fig. 3 is an enlarged fragmentary exploded view of one of the stationary'grate bars;

Fig. 4 is an exploded sectional'view taken alon the line IV-IV of Fig. 3, looking in the direction indicated by the arrows; and

Fig. 5 is an enlarged fragmentary sectional view taken along the line VV'of,Fig; 2, looking in the direction indicated by the arrows.

Referring now to the drawings more indetail;

thereference character In indicates, in its entirety, stoker mechanism of the sprinkler or spreader type and including grate structure ll disposed within a furnace 12 which hasthe usual side walls 13, rear wall Hand front wall [5. The

latter is provided with an opening I6 through which fuel is impelled by the blades [1 of the rotary impeller Hi, to the fuel supporting'surface 0f the grate structure ll. The mechanism for feeding fuel into the furnace through the front wall opening 16 forms no part of the present invention and, therefore, is not further described herein. However, if desired, it may take the form disclosed in applicant's copending application, Serial No. 549,848, filed August 1'7, 1944.

The grate structure ll comprises a plurality of reciprocatory grate bars 20 alternating with stationary grate bars 2| and disposed in sideby-side relation. While in the arrangement here in illustrated, alternate bars are reciprocating and the remaining bars stationary, it will be apparent that this particular arrangement of reciprocatory and stationary bars may be varied if desired.

As best shown in Fig. 2, the bars are composite and of inverted V form and extend transversely of thefurnacewith the central apex substantially aligned with the longitudinal center of the'furnace, directly to the rear of the fuel feed opening it in the furnace front wall I5. All of the bars rest at their outer ends on supporting plates 22, having disposed therebeneath and therebeyond conventional dump plates 23, carried by oscillatable shafts 24.

Each composite reciprocatory bar 20 includes a'central upper member 26 having lateral downwardly-inclined side portions 21, an end bar member 28 and one or more intermediate bar members 29, together with a supporting rod or strip 30' disposed beneath the bar members 26, 28 and 29 and secured thereto by suitable means, such as the pins 3| extending therethrough and through depending lugs 32 aligned therewith. Each of the bar members 26, 28 and 29' is of inverted U cross section and comprises an upper fuel-supporting portion 34, depending side members 35 and 35 and laterally extending ribs 31 and 38 (Figs. 1 and 5). The supporting rod 30 is disposed between the depending side pieces 35and'35' and is secured thereto by the pins 3|, as previously indicated.

Preferably, each of the end bar members 28 and intermediate bars members '29 are provided at their upper ends with projections 39 and 40, respectively, adapted to be received in mating recesses 4-1 and 42 provided in the adjacent ends of the bar members next thereabove.

Each central upper member 26 is provided with a depending transversely-extending web or rib 44 having a notch 45 formed in its lower surface for reception of the upperflange 45 of a structural I member 47 which extends longitudinally of the grate structure I! and is supported for limited transverse reciprocatory movement upon, and fixed to, a plurality of carriage structures 48, supported on rollers 49 mounted upon shafts 50 carried by frame structures 5|, which in turn are supported by a pair of longitudinally-extending structural members 52.

The frames 5! carry bearings 53 for a shaft 54 extending from front to rear of the furnace and having keyed thereto a plurality of crankarms 55, connected through links 56 with the carriages 48, whereby limited oscillatory movement of the shaft 54 produces corresponding lateral reciprocatory movement of the I-beam 47. Inasmuch as the upper flange 46 of this beam is received in the groove 45 in the depending lugs 44 of the reciprocatory bars 20, the latter will have reciprocatory motion imparted thereto. Limited oscillatory movement is imparted to the shaft 54 by the stoker drive engine 60, through gearing BI and linkage 62 and 63. I

The space below the grate structure H is provided with a pair of longitudinally extending walls 65 and B6 of masonry or other suitable material, with structural members 6'! and 68 disposed thereon, and, the combined structure forming vertical supports for the supporting plates 22,

, on which the outer ends of the grate 'bars rest.

A pair of longitudinally-extending partitions 10 and II divide the space below the grate structure II and between the vertical walls 65 and 66 into a central plenum chamber 12 and side plenum chambers 13 and M. V partitions 1B and H abut the lower fiangeslof structural memberslS and I6, respectively, which serve as intermediate'supports for the stationary bars 2|. 7 i

, Suitable means (not shown) may be provided for controlling the relative supplies of air to the three plenum chambers l2 l3 and I4. Inasmuch as, under certain operating conditions, the quantities of air supplied to the various plenum cham- "bers may differ, it is desirable to prevent, insofar as possible, leakage of air from one chamber to spaced ears Bl straddling the supporting rod i and secured to the latter by pins '82, the ears 8| fitting between the depending side pieces and 36 of the grate bar member. The lower portion of the depending block 80 1s provided with a transversely-extending slot 83, in which is positioned q a sealing member 84 in the form 'of a trans- The upper edges of the. 7

path extending from front to rear of the grate structure in overlying relation to the central plenum chamber 12. The transverse movement of the'reciprocatory alternate bars 20 with respect to the stationarybars 2|,feeds the fuel laterally in both directions from the central zone overlying the central plenum chamber, across the end bars 28 overlying the side plenum chambers 13 andl l, to'the dump plates 23.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so, limited, but is 'susceptible of various changes and modifications without departing from the spirit thereof, and it @is'desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What is claimed is:

1. In a furnace, grate structurecomprising a plurality of transversely-extending grate .bars of inverted-V shape disposed in side-by-side relation, a'number of said bars being transversely reciprocable and being interspersed among the" remaining stationary bar s; wall structure cooperversely-extending strip, which, as the bar reciprocates, is adapted to slide back and forth across the plates 1'! forming the top Wallof the partitions l6 and H. a

The stationary bars 2! are very similar in strucmm to the reciprocatory bars 20 except that they omit the depending'web or rib 4 4, as shown in Fig. 3, and are provided with intermediate depending support members 86 and 81 adapted to rest upon the upper surfaces of thestructural members 52,15 and 16. i

The sealingstructure for the stationary bars differs from that of the reciprocatory bars in that, inasmuch as they do not move, floating sealing member 84 is omitted. Instead, the depending web 36 directly engages the plates 11,

ating with the grate structure to provide beneath the latter a plenum space; a pair of partitions disposed longitudinally of the plenum space and extending from the bottom of said space to points adjacent the under surfaceof the grate structure, said partitions separatingthe plenum space into a central plenum chamber and a pair of side plenum chambers; andfa sealing member carried'by and-depending from-each of the grate bars and sealing the space between said bars and the tops of the partitions there-, beneath,whereby flow of air from one plenum chamber to another is prevented. a Y I 2. In a furnace, a grate structurecomprising I aplurality of transversely-extending grate-bars I of inverted-V shape disposed in side-by-side relation, a number of said bars being transversely reciprocable-and being interspersed among the remaining stationary bars; a pair of structural members'extending longitudinally ofthe furnace grate structure beneath the latterto supportfthe stationary bars from beneath at points intermediate their apexes and ends; a pair'of longitudinal partitions extending downwardly from the pair of structural supporting members and separating the space beneath the grate structure into a central plenum chamber .and a pair of-side plenum chambers, and separate sealingmembers carriedby each of the bars for preventing flow of air from one plenum chamber to another between' the top of'th'e structuralsupporting members andthe bottom of said bars. a

carried by the top of the structural member I5.

of the rotary impeller l8 rearwardly through thefurnace front wall opening [6 onto the upper surface of the grate structure ll, along a central the reciprocable bars automatically maintain 3. Structure as specified in claim 2, wherein'the structural supporting 'members have horizontal upper surfa ces against which the sealing members abut, and the sealing members carried by sealing engagement with said horizontal surfaces during reciprocation of the bars. 7 1

I DONALD J 'MOSSHART. 

